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Patented July 15, 1924.

UNITED STATES PATENT OFFICE.

JOHN H. HUNT, OF DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO DELCO-LIGHT COMPANY, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

IGNITION SYSTEM.

Application filed. March 26, 1919. Serial No. 285,270.

To all whom it may concern:

Be it known that I, JOHN H. HUNT, a citizen of the United States ofAmerica, residi at Dayton, county of Montgomery, State of Ohio, haveinvented certain new and useful Improvements in Ignition Sys-,

toms, of which the following is a full, clear, and exact description.

, This invention relates to ignition systems for internal-combustionengines, and the chief object is to provide ignition for an engine byutilizing a source of current supply at relatively high voltage.

In carrying out this object I use an ignition coil and timer which arestandard as regards the usual types of ignition systems operating onrelatively low voltages, and a.

' of the present invention will be apparent from the followingdescription, reference being had to the accompanying drawings, whereinpreferred embodiments of the present invention are clearly shown.

In the drawings Figs. 1 to 4. are wiring diagrams showing difierentforms of the invention.

In each figure of the drawings a highvoltage battery or other source ofcurrent at a voltage considerably higher than ordinarily employed forignition circuits is grounded at 21, and is connected with an inductivewinding 22 wound about a closed magnetic circuit 28. Inductance 22 isconnected with resistance 24 which in vturn is connected with ignitioncoil primary 25. Primary 25 is connected with an engine controlled timer26 connected by ignition switch 27 with a ground connection 28. Acondenser 29 is shunted around the timer 26. Ignition coil secondarywinding 30 is connected with a spark gap or spark plug 31.

The ignition coil, being a standard type of coil used for low voltageignition has a high transformation ratio. For this reason, if theinductance 22 were not placed in circuit with the coil, a highsecondaryvoltage would be produced at the instant of the closing of the timercontacts, and a spark would occur prematurely at the gap or plug 31. Theinductive winding 22 is constructed so as to have a high inductance whenthe ductance 22 in direct ratio to their inductance at time of closingof timer contacts. Inductance 22 and core 23 are constructed andarranged so that the magnetic circuit is saturated at very low currents,that is, at a fraction of the maximum current normally flowing throughit, so that the total energy stored in it, which would react on thetimer contacts when the circuit is opened, can be limited, to a valueinsufficient to cause arcing at the opening of the timer contacts.

By way of illustration, the dimensions of some of the electrical unitsare given: The ignition coil primary 25 may have 260 turns of number '20wire, and the secondary 30 may have 12000 turns of number 36 wire. Theinduction winding 22 may have an inductance of 148 millihenries and maycomprise 348 turns of number 20 wire. The core 23 is laminated'and has across-section 5; inches square, and an opening 21% inches by f}; inch.

In Figs. 2 to 4 are shown various devices for obtaining a discharge ofenergy from the inductance 22 at the time of break in a manner such asto obtain a clean or substantially arcless break of the timer contacts.In Fig, 2, a capacity 34 of 20 microfarads is connected in parallel withwinding 22. In Fig. 3, the discharge is across carbon blocks 35 and 36separated by mica insulation 37 .00l-inch thick and provided with adischarge path or hole 38-inch in diameter. One or both of. said carbonblocks may be vented in a suitable manner to provide for the escape ofheat generated by the discharge. In Fig. 4 a secondary inductance 40comprising 3500 turns of number 36 wire cooperates inductively withwinding 22 to effect a discharge at the time of break of the primarycircuit across a brass ball gap of .006 inches, the balls ll and 42being {3-inch in diameter.

It is to be understood thatthe invention is not limited to thedimensions given or to the materials described, but that variations ofdimensions and substitutions of materials 'may be made in order to suitthe requirestructed in accordance with the foregoing description havebeen found to operate satistactorily at volts, but it is to beunderstood that primary current at voltages which vary somewhat fromthis value can be employed by making the necessary varia tions in thedimensions of some or the electrical units.

It has been found expedient to provide a discharge gap for theinductance 22 which will discharge at a value slightly above batteryvoltage, for example, at volts where the battery voltage is 110 volts.

lt is apparent from the foregoing description that the present inventionprovides for the suppression or" ignition at the time of closing of thetimer contacts while permitting the contacts to open Without unduearcing. These provisions permit the use with high voltage primarycircuits of ignition coils which are constructed for use with theordinary low voltage circuits with out change in the construction of thecoil.

/Vhile the forms of mechanisms herein shown and described constitutepreferred forms of embodiments of the invention, it is to be understoodthat other forms might be adopted, and various changes and alterationsmade in the shape, size, and proportion of the elements therein withoutdeparting from the spirit and scope of the invention.

What I claim is as follows:

1. in an ignition system, the combination with an ignition coil having arelatively high transformation ratio; a timer; a current source ofrelatively high voltage; and electrical means for suppressing ignitionat the closing of the timer contacts.

2. In an ignition system, the combination with an ignition coil having arelatively high transformation ratio; .a timer; 2:. current source ofrelatively high voltage; and an inductance in series with the ignitioncoil primary winding for suppressing ignition at the closing of thetimer contacts.

3. In an ignition system, the combination with an ignition coil having arelatively high transformation ratio; a timer; a current source ofrelatively high voltage; an inductance in series with the ignition coilprimary winding for suppressing ignition at the closing of the timercontacts; and means for effecting discharge of said inductance at thetime of opening or said timer contacts in order to prevent arcing atsaid contacts.

In an ignition system, the comhinatron with an i nition 0011 having arelat rely high transrormation ratio; a timer; current source ofrelatively high voltage; an. inductance in series with the ignition coilprimary winding for suppressing ignition at the closing of the timercontacts; and a discharge gap connected with said inductance providingfor the discharge of said inductance at a voltage slightly above thevoltage of said current source.

5. In an ignition system, the combination with an ignition coil havingrelatively high transformation ratio; a timer; a cum rent sourceofrelatively high voltage; an inductance in series with the ignition coilprimary winding tor suppressing ignition at the closing of the timercontacts; and a discharge consisting of carbon hloclrs separated byinsulation having a discharge passage in alinernent with said blocks;

6. in an ignition system, the combination with an ignition coil having arelatively high transformation ratio; a timer; a current source ofrelatively high voltage; an inductance in series with the ignition coilprimary winding for suppressing ignition at the closing of the timercontacts; a secondary inductance cooperating with said seriesinductance; and a discharge gap for said secondary inductance.

In an ignition system, the combination with an. induction coil; a timer;a current source of relatively high voltage; and electrical means forsuppressing ignition at the closing of the timer contacts.

8. in an ignition system, the combination with an induction. coil; atimer; a current source of relatively high voltage; an electrical meansfor suppressing ignition at the closing of the timer contacts and forsuppressing arcing the opening of the timer contacts.

9. in an ignition system, the combination with an induction coil; atimer; current source oi relatively high. voltage; and a varyinginductance for suppressing ignition at the closing of the timercontacts.

10. in an ignition system, the combination with an induction coil; atimer; a current of relatively high voltage; and an inductance for suppossing ignition at the closing of the timer contacts, said inductancebeing relatively larger at low current values than t igh current values.

1 testimony whereof in";

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